/**
 * Wire-level transport counters for the SDK's reconnect + replay path.
 *
 * Three counters expose the contract `task.resubscribe` flow has with
 * QAR's per-session replay buffer: how many resubscribes the SDK has
 * sent, how many replayed envelopes have come back, and how often the
 * anchor `since_message_id` rotated out before the SDK could
 * re-anchor.
 *
 * The counters are wire-agnostic — they live next to the spans the SDK
 * already emits (`src/observability/spans.ts`) rather than inside the
 * connection itself so consumers can read them off `client.transportMetrics`
 * without holding a reference to the WS layer.
 *
 * Backing storage is in-memory. The SDK does NOT shovel these into an OTel
 * meter — consumers wanting Prometheus/StatsD scrape paths read the values
 * via {@link TransportMetrics.snapshot} and forward them through their own
 * exporter. (OTel's metrics API is a heavier surface than the SDK's tracing
 * peer-dependency posture wants to pull in for three counters.)
 */
/**
 * Snapshot of every counter at a point in time. Counter names are
 * wire-aligned with QAR's runtime documentation: `*_total` suffix per the
 * OpenMetrics convention, even though the SDK doesn't ship them through an
 * OTel meter — the suffix is part of the published name so consumers
 * forwarding to Prometheus get the canonical metric name without renames.
 */
export interface TransportMetricsSnapshot {
    /** Envelopes received via `task.resubscribe` replay (descendants of an anchor). */
    readonly replay_envelopes_received_total: number;
    /** `task.resubscribe` envelopes emitted by the SDK (auto-replay + manual). */
    readonly resubscribes_sent_total: number;
    /**
     * Inbound `error { code: "replay_anchor_missing" }` envelopes from QAR.
     *
     * Defensive wiring — no released QAR emits that code, so this stays at
     * zero. Don't alert on it, and don't read zero as "no anchor misses."
     * See `docs/sdk2/reconnect-replay.md` §When the replay anchor is stale.
     */
    readonly replay_anchor_missing_total: number;
}
/**
 * In-memory counter store. One instance per `QodoClient` — survives
 * reconnects so the counters accumulate across the client's lifetime.
 *
 * The store is intentionally minimal: three monotonic counters + a
 * `snapshot()` reader. No reset, no labels, no histograms. Consumers
 * wanting label dimensionality (per-session, per-task) read the per-event
 * span attributes instead — the counters are the aggregate roll-up.
 */
export declare class TransportMetrics {
    private replayEnvelopesReceived;
    private resubscribesSent;
    private replayAnchorMissing;
    /** Increment per inbound envelope that arrived via a `task.resubscribe` replay window. */
    recordReplayEnvelopeReceived(): void;
    /** Increment per outbound `task.resubscribe` envelope written to the wire. */
    recordResubscribeSent(): void;
    /**
     * Increment per inbound `error { code: 'replay_anchor_missing' }` envelope.
     * Defensive — no released QAR emits that code. See
     * {@link TransportMetricsSnapshot.replay_anchor_missing_total}.
     */
    recordReplayAnchorMissing(): void;
    /** Read every counter atomically — single-threaded JS, so this is a copy. */
    snapshot(): TransportMetricsSnapshot;
}
//# sourceMappingURL=transportMetrics.d.ts.map